Make per_pixel_transparency always enabled in the editor

[YeldhamDev]

A (fashionably late) follow-up to #91333. This makes so that window transparency is always enabled in the editor itself, which is necessary for popups to have shadows.

Requires #106344 (see below).

[akien-mga]

Didn't we conclude that this wasn't a good option because per-pixel transparency isn't properly supported on Windows + Nvidia + Vulkan, which is by far our most frequent user setup?

• Makeper_pixel_transparency enabled by default #101252

I still think it would be preferable to remove popup shadows from the editor theme so this isn't necessary. At least until we can ensure that per-pixel transparency works everywhere and has no significant performance impact.

See:

• Window per-pixel transparency does not work on hybrid GPU systems (NVIDIA Optimus) #76167 (not sure if the "Optimus" part is still relevant, a lot of recent reports don't mention a laptop / hybrid / Optimus setup).

[KoBeWi]

The way you implemented it, the transparency will be always enabled in editor builds, not only in the editor.
You could just use editor_hint feature override for that.

[YeldhamDev]

Didn't we conclude that this wasn't a good option because per-pixel transparency isn't properly supported on Windows + Nvidia + Vulkan, which is by far our most frequent user setup?

I can add a small check to see if it's on Window with Vulkan, and then not enable it.

I still think it would be preferable to remove popup shadows from the editor theme so this isn't necessary. At least until we can ensure that per-pixel transparency works everywhere and has no significant performance impact.

Is the performance impact really that severe, considering this version is only for the editor? I feel like having the popups be shadowless makes them look really flat and unpolished.

[YeldhamDev]

@KoBeWi Thanks, fixed.

[YeldhamDev]

I'm not sure why this is causing a memory leak.

[bruvzg]

Didn't we conclude that this wasn't a good option because per-pixel transparency isn't properly supported on Windows + Nvidia + Vulkan, which is by far our most frequent user setup?

We can probably force it to work, using NVAPI (which is already used for OpenGL), I'll check it. Setting "Vulkan/Opengl present method" to "native" should make transparency work with Vulkan. If it's overridable via API it can be used.

I'm not sure why this is causing a memory leak.

Seems like it's existing one, not introduced by this PR, probably fixable by something like:

diff --git a/platform/linuxbsd/x11/gl_manager_x11.cpp b/platform/linuxbsd/x11/gl_manager_x11.cpp
index 41c8cd704b..151730b9a2 100644
--- a/platform/linuxbsd/x11/gl_manager_x11.cpp
+++ b/platform/linuxbsd/x11/gl_manager_x11.cpp
@@ -137,6 +137,10 @@ Error GLManager_X11::_create_context(GLDisplay &gl_display) {
                ERR_FAIL_NULL_V(fbc, ERR_UNCONFIGURED);

                for (int i = 0; i < fbcount; i++) {
+                       if (vi) {
+                               XFree(vi);
+                               vi = nullptr;
+                       }
                        vi = (XVisualInfo *)glXGetVisualFromFBConfig(x11_display, fbc[i]);
                        if (!vi) {
                                continue;

[bruvzg]

#106344 should fix the transparency issue on NV + Vulkan.
#106345 should fix the leak.

[YeldhamDev]

@bruvzg You're the best!

[lawnjelly]

This may not be cheap AFAIK and should be benchmarked on different hardware / platforms imo.